169 grammar points. Filter by level, search, and hover or tap a card to peek.
169 points
Answer one question and this starts counting.
Start with a grammar pointProgress and your review deck live in this browser only. Save a file to keep a copy, or load one to bring them back.
make it a rule to / have a personal habit of
〜ことにしている shows a habit or personal rule that you decided on by yourself and still keep now. 〜ことにする is the decision itself, and している shows that the decision continues as a habit. It is used for things you can control, such as exercise, food, money, or study. With the ない form it means 'I make it a rule not to do ...'.
be supposed to / it is the rule (or the plan) that
〜ことになっている explains a rule, a custom, or a schedule that has already been decided and is in effect now. The decision was made by a group, an organization, or society, not by the speaker's own will. It is often used to explain the rules of a school, a company, or a country to someone. It is also used for a fixed plan, as in 'it has been arranged that I will ...'.
be designed / made so that
〜ようになっている explains how a machine, a tool, or a system works: it is made so that something happens, or does not happen, automatically. It describes the design, not a person's will or effort. It is often used with 〜と or 〜ば to give the condition: 'when you do A, B happens'. You see it in instructions and in explanations of products and services.
I hope ... / May ... (wish, prayer)
〜ますように is used to make a wish or say a prayer. You use it for things you cannot fully control, such as passing an exam, the weather, health, or luck. The words 祈っています (I am praying) are left out after ように, so the sentence stops there. Even when you talk to yourself or to friends, the verb before ように stays in the ます form.
such as / like (giving an example)
This use of ような / ように gives a concrete example to show what kind of thing you mean. In AのようなB, A is one real example of the group B: 東京のような大きい町 means 'big cities, for example Tokyo'. AのようにB gives A as a model for an action or a state: 'in the way A does'. After a verb, 〜ような + noun shows the kind of thing by describing a typical case.
as (you know / I said / shown in ...)
This ように means 'as' or 'in the same way as'. It points to something the listener already knows, has heard, or can see (what someone said, a picture, a table, a manual), and the main clause says something that matches it. It is often used as an opening phrase before the main point, as in ご存じのように (as you know) and 前にも言ったように (as I said before). It also tells someone to do something in the same way as a model: この絵のように (like this picture).
try to / be about to
〜（よ）うとする shows that someone makes an effort or a move to do something, but the action is not finished yet. It has two main meanings: 'try to do' (often the try fails) and 'be just about to do' (the moment right before an action, often with とき or たら). The negative 〜（よ）うとしない means that a person shows no will to do something. It is usually said about other people, often as a complaint.
there are times when / sometimes
Dictionary form or ない form + ことがある says that something happens sometimes; it is not regular, but it is not zero. It is used for occasional actions, exceptions to a habit, and things that can happen from time to time. Be careful with the form of the verb: with the た form (行ったことがある) the meaning changes to a past experience, 'have done before'.
causative of emotion: make someone feel (worry, laugh, cry ...)
With verbs of emotion, the causative form does not mean 'order' or 'allow'. It means that a person, an action, or an event is the cause of someone's feeling: 'A makes B worry / laugh / cry / angry / happy'. Nobody is forcing anyone; the feeling comes up naturally as a result. It is often used with 〜てしまう for regret and with 〜たい / 〜たくない for what you want to do for other people.
be allowed to do / someone kindly lets me do
This pattern joins the causative ('let someone do') with もらう / くれる ('receive / give a favor'). It means that someone allows me to do what I want to do, and I feel thankful for it. With もらう, I am the subject: I receive the permission. With くれる, the person who allows it is the subject. The action itself is always done by me (or someone on my side), not by the person who gives permission.
humbly do (with your permission)
〜（さ）せていただく is the humble form of 〜（さ）せてもらう. The speaker talks about his or her own action in a humble way, as something done with the listener's permission or thanks to the listener's kindness. It is common in business, in shops, and in speeches: to announce what you are going to do (始めさせていただきます), to report what you were allowed to do, and to ask for permission politely. The person who does the action is always the speaker (or the speaker's side).
spontaneous: naturally come to think / feel / remember
The spontaneous use of 〜（ら）れる shows that a thought or a feeling comes up naturally, by itself, without the person trying. 昔のことが思い出される means 'memories of the past come back to me (I cannot help it)'. 〜と思われる and 〜と考えられる are common in news, reports, and essays: they give an opinion in a soft and objective way, as a conclusion that anyone would naturally reach. This use belongs mostly to written or formal language.
It is said that / people say that
Use 〜と言われている for something that many people say or believe in general. It is the passive of 言う, so the sentence does not name who says it. It is common for general knowledge, old stories, and a person's or place's reputation. The speaker does not say whether it is really true.
Do ... (for me) — blunt request
〜てくれ is the plain, strong way to ask someone to do something for you. くれ is the command form of くれる. It is used mainly by men, to close friends, family, or people below them, and it sounds rough to anyone else. It also appears in reported speech, as in 〜てくれと言われた. There it only shows that a request was made, so anyone can use it.
Try doing ... (said gently to a child or junior)
〜てごらん gently tells the listener to try doing something. It is a softer way to say 〜てみなさい. Parents say it to children, teachers to students, and older people to younger people. It is not used to people above you, and you cannot use it for your own actions.
Honorific: お持ちですか / お待ちです
お〜です is a short honorific form for the action or state of a person you respect. It most often has the meaning of 〜ています: お持ちですか means 持っていますか. With some verbs it shows something happening now or soon, or already done, as in お出かけですか and もうお帰りです. It is very common in shops, hotels, and offices. Verbs with a one-sound stem, such as 見る and いる, usually do not take this form.
Extra-polite speech: でございます / ております / まいります
These words make your speech very polite toward the listener. Use them for your own actions, for people on your side such as family and coworkers, and for things and events, as in 電車がまいります. They are common in shops, on the phone, in announcements, and in speeches. They do not show respect to the person who does the action, so do not use them for the listener's actions or for a person you respect.
Spoken short form of 〜てしまう
〜ちゃう and 〜じゃう are the short spoken forms of 〜てしまう and 〜でしまう. The meaning is the same: an action is finished completely, or something happens that the speaker did not want or plan. They are used in everyday talk with friends and family. With ます (〜ちゃいました) they are still casual, so use 〜てしまいました in formal situations and in writing.
Spoken short form of 〜ておく
〜とく and 〜どく are the short spoken forms of 〜ておく and 〜でおく. The meaning is the same: do something ahead of time to get ready, or leave something as it is. They are used in everyday talk. Similar short forms are 〜てる for 〜ている (見てる) and 〜てく for 〜ていく (持ってく). In formal speech and in writing, use the full forms.
Have to / must (casual speech)
These are spoken short forms that mean 'have to'. 〜なくちゃ comes from 〜なくては, 〜なきゃ comes from 〜なければ, and 〜ないと is 'if I don't ...' with the ending left out. The ending いけない / ならない is often dropped, so the sentence can end with 〜なくちゃ, 〜なきゃ, or 〜ないと. People often use them to talk to themselves or to close friends about what they must do.
Speaking of ... / What is ...? (casual topic marker)
This って brings up a topic in casual speech. It is the spoken form of 〜は or 〜というのは. People use it to ask what a word means, to ask about a person or thing, or to give their feeling or opinion about it. It is not used in formal speech or writing.
What was it again? / Was it ...? (trying to remember)
〜っけ is put at the end of a sentence when you are trying to remember something that you knew or heard before. You can say it to yourself, or you can ask the listener to check your memory. The た-form is often used even for present or future things, because you are recalling what you learned in the past. It is a spoken form; with でしたっけ / ましたっけ it can be used politely in conversation.
Because ..., you know (casual reason or excuse at the end of a sentence)
〜もの / 〜もん at the end of a sentence gives a reason in casual talk. It often sounds like an excuse, a complaint, or 'of course, because ...'. It is often used together with だって at the start. もん is more casual and is used a lot by children and young people; もの sounds a little softer and is used more by women. Do not use it in formal situations.
Even if / no matter how (casual 〜ても)
〜たって and 〜だって are the casual spoken forms of 〜ても and 〜でも. They mean 'even if' or 'even though': the result does not change. They are often used with いくら, どんなに, or a question word. A noun + だって also means 'even ...' or '... too', like 〜でも / 〜も. In formal speech and in writing, use 〜ても / 〜でも.
while / during (the whole time vs. at some point)
間 is a period of time with a start and an end. A 間、B means that B goes on from the start to the end of A, so B often has ずっと or a form like 〜ていた. A 間に、B means that B happens, or is finished, at some point before A ends. The subjects of A and B can be different people. At N3 it is usually written with the kanji 間, and you must choose between 間 and 間に by looking at the main clause.
while still ... / before it changes
A うちに、B means 'do B while A is still true, before A changes'. The speaker feels that after the change it will be too late, difficult or not as good, so B is often advice, a plan or a request. With the ない-form it means 'before ... happens': 忘れないうちに = before I forget. This is a different use from the うちに that shows a gradual change, as in 話しているうちに仲良くなった.
while doing ... (something changes without being planned)
A うちに、B means that while A continued, B happened naturally, often little by little or before the speaker noticed. B is not something the speaker decided to do. The ない-form gives phrases like しばらく会わないうちに (while we had not met for some time) and 気がつかないうちに (before I noticed). This is a different use from the うちに that means 'before it changes', as in 忘れないうちにメモする.
right in the middle of (doing)
最中 means the point when an action is most active. A 最中に、B says that B happened right in the middle of A. B is often something sudden that stops or disturbs A, such as a phone ringing or an earthquake. 〜最中だ at the end of a sentence tells the listener that you are busy with something right now.
just when / right at the moment that
This pattern grows out of 〜ところだ. ところ is a scene or stage of an action (about to do, doing, just did), and the particle links that scene to the next event. With に or へ, something arrives at that scene: a person comes, or a call comes in. With を, the scene is the object of the next verb: someone sees it, finds it or helps in it. The second event often changes or stops what the person was doing.
the moment ... / as soon as (something unexpected happened)
A たとたん、B means that B happened at almost the same moment as A finished. B is a sudden change or event, and the sentence carries the speaker's surprise. Because B is something the speaker noticed, not something the speaker chose to do, the main clause is not a plan, a request or an order. The pattern is used for things that have really happened, so the sentence usually ends in the past.
not until after ... / unless you first ...
A てからでないと、B means that B is impossible or not allowed unless A is done first. A is a necessary condition, and B is a negative or unwanted result: 〜できない, 〜てはいけない, 無理だ, 困る. The real message is positive: 'do A first, and then B becomes possible'. It is often used for rules, for permission, and for explaining why you cannot answer or decide yet.
only after ... did I (realize / experience)
A てはじめて、B means that B did not happen before A, and A was the experience that made B happen for the first time. It is often used when you look back and say that you did not understand something until you experienced it yourself. B is a realization or a new situation, not an action you plan to do or ask someone to do.
ever since
A て以来、B means that the same situation B has continued all the time since A happened. A is an event at some distance in the past, not something from a few hours ago. B is not an action done only once, and the pattern is not used for the future. It sounds a little formal, and it is common in writing and in polite talk.
every time
A たびに、B means 'every time A happens, B happens too'. A is something that happens again and again, and B follows it each time. B is often a feeling, a memory or a change that comes naturally (思い出す, 緊張する, 〜なる), but it can also be something the speaker always does on that occasion. It is not used for one single occasion; for that, use とき.
while you're at it / on the occasion of
A ついでに、B means 'while doing A, I also do B, because it is a good chance'. A is the main thing you planned to do, and B is an extra action that is easy to add because you are doing A anyway. B is something a person does on purpose, so things that just happen, like rain starting, do not come after ついでに. It is very common in requests such as 〜ついでに、〜てくれない？
when / on the occasion of (formal)
〜際（に） means the same as 〜とき, 'when / at the time of', but it is formal. It is common in notices, announcements, instructions, business emails and polite speech, and it is often followed by a request or a rule (〜てください, 〜ないでください). It is used for a particular action or occasion, such as using, leaving or applying, and it is usually not used for ages or states like 子ども or 若い. In casual talk with friends, とき is the natural choice.
From ... through ... (a rough range)
Shows a rough range of time or place. Something continues, or happens here and there, through that range. The start and the end are not exact points, so this pattern is common in weather forecasts and news. It is also used for a part of the body (肩から背中にかけて).
Every / each
ごとに has three uses. With a plain noun it means 'for each one' or 'one by one as a unit' (クラスごとに = class by class). With a number it means that something is repeated at that regular interval (15分ごとに = every 15 minutes). With a verb it means 'every time someone does it', and something usually changes little by little.
At intervals of / every other
おきに comes from 置く (to leave) and means 'leaving that much in between'. With days, weeks, months, years, and things you count one by one (lines, seats), that number is skipped: 1日おきに is 'every other day', and 1行おきに is 'on every other line'. With minutes, hours, and distance, it usually means the same as ごとに: 10分おきに is 'every 10 minutes'.
For the first time in ... / after an interval of ...
ぶり shows that something happens again after that length of time. For that whole time it did not happen, and the speaker usually feels that the time was long. 5年ぶりに国へ帰った means 'I went back to my country for the first time in five years'. It is about one event that happens again now, not about a repeated schedule.
Just like / as if (simile)
This pattern compares something to a thing that it is not: 'it is just like ...', 'it is as if ...'. まるで makes the comparison strong and tells the listener that it is only a comparison, not a fact. みたいだ is casual and used in conversation; ようだ is also used in writing. Note that まるで + negative (まるで分からない) is a different use that means 'not at all'.
Typical of / just like a real ...
Noun + らしい says that a person or thing has the qualities that people expect from that noun. The person or thing really is that noun: 春らしい天気 is said in spring, and 子どもらしい is said about a child. It usually sounds positive. The negative 〜らしくない means 'not like what we expect from ...', as in 田中さんらしくない (that's not like Mr. Tanaka).
-ish / looks like / tends to
っぽい makes a word that describes how something looks or feels. With a noun, it means 'looks or feels like ...': 白っぽい is 'whitish', and 子どもっぽい about an adult means 'childish'. It is often used when the person or thing is not really that noun, and it often sounds negative, but not always: 大人っぽい can be praise for a young person. With the ます-stem of a few verbs, it describes a person who does that easily, like 忘れっぽい (forgetful). It is casual and very common in conversation.
Tend to / often (something not good)
がち says that something often happens, or that people easily fall into doing something. It is usually used for things that are not good or not wanted, such as being late, forgetting, being sick, or not getting enough exercise. It can describe a general tendency (冬は運動不足になりがちだ) or a person's recent pattern (最近、授業を休みがちだ). がち means 'often', not 'always' or 'every time'.
Slightly / a touch of
気味 (read ぎみ here) says that someone or something is a little in a certain state. It is usually used for states that are not good, especially health, feelings, and plans: 風邪気味 (a slight cold), 疲れ気味 (a bit tired), 遅れ気味 (a little behind). It often comes with 少し or ちょっと. Because it means 'a little', it is not used for a very strong or serious state. The 気味 in 気味が悪い is read きみ and means something different ('creepy').
Covered with / full of (something unwanted)
だらけ says that there is a lot of something all over a place or thing, often more than you want. It is usually used for dirty or unwanted things, such as mud, dust, trash, mistakes, and scratches: 服が泥だらけになった means 'my clothes got covered in mud'. The speaker often feels that it is too much or unpleasant. For nice things, いっぱい is usually used instead.
Have (a shape, color, face, voice)
〜をしている describes how a person, animal, or thing looks or what it is like: its shape, color, face, eyes, voice, and so on. Here する is not an action; it shows a quality that the person or thing has. It is usually used as をしている / をしていた (or をした before a noun), and the noun needs a word that describes it: 丸い形をしている, not just 形をしている. In English, 'have' or 'look' is often the best translation: 青い目をしている means 'has blue eyes', and 疲れた顔をしている means 'looks tired'.
Pretend to / act as if
〜ふりをする means 'to pretend': to act as if something is true when it is not, so that other people believe it. 知らないふりをする means that the person really knows but acts as if he or she doesn't. It is used for people, and sometimes animals, who act that way on purpose. The past ふりをした and the continuing ふりをしている are very common.
have a feeling that
Use 〜気がする when you feel that something is so, but you have no clear reason or proof. It is softer and less sure than 〜と思う. Adding ような (〜ような気がする) makes the statement even vaguer. The feeling is the speaker's own.
it seems that (from what I can tell)
どうやら and どうも are adverbs that go together with a guessing ending such as らしい, ようだ or みたいだ. They show that the speaker is not sure, but is guessing from what he or she sees, hears or feels. どうも often adds the feeling "I can't say exactly why, but…". The adverb comes early in the sentence, so the listener knows that a guess is coming.
look about to ... any moment
This is the 〜そうだ of appearance ("looks like it will…") with the adverb 今にも added. 今にも means "at any moment", so the whole pattern says that something looks as if it will happen right now, in front of your eyes. It is used with verbs and describes what the speaker sees or feels at that moment.
unlikely to / shows no sign of
This is the negative of the 〜そうだ of appearance when it follows a verb. It means that, judging from the present situation, something is unlikely to happen or there is no sign that it will happen. 〜そうにない and 〜そうもない have almost the same meaning. For adjectives a different negative is used (おいしくなさそうだ).
almost (did) / nearly
〜そうになる means that something came very close to happening, but in the end it did not happen. It is usually something the speaker did not want or could not control, such as falling, crying, forgetting or being late. The 〜そうだ of appearance ("looks about to") is combined with なる ("become"), so it describes the moment when the situation reached that point.
nearly / would have (but didn't)
With もう少しで or a たら / ば clause, 〜ところだった means that something almost happened, but in the end it did not. It is usually a bad result that the speaker escaped, so it often sounds like "That was close!" With a good result, it shows regret: もう少しで勝つところだった (we nearly won). Be careful: without these hints, 〜ところだった can also be the simple past of the N4 〜ところだ, meaning "was just about to".
do completely / cannot finish
〜きる means to do something all the way to the end, so that nothing is left: 使いきる (use it all up), 読みきる (read it to the last page). 〜きれない means you cannot finish because there is too much or it is too hard: 食べきれない (too much to eat), 数えきれない (too many to count). With some verbs, 〜きる shows a very strong state: 疲れきる (be completely tired out).
half-done / in the middle of / about to
〜かける means that an action has started but has not finished. It is often used when you stopped in the middle, or when something is left half-done: 読みかけの本 (a book I am partway through). With verbs of change, 〜かけている means that the change has already begun and is close to its end: 電池が切れかけている (the battery is almost dead). 〜かけの is the noun-like form used before a noun.
freshly / just done
〜たて means that something has just been done, so it is still fresh or new. It is mostly used for food (焼きたて, 作りたて, 取れたて), for things that were just washed or painted (洗いたて, 塗りたて), and for people who have just started something (生まれたて, 入社したて, 覚えたて). It describes the fresh state of the thing or person, and it usually sounds positive for food.
hard to (physically / mentally)
〜づらい means that doing something is hard because it causes the speaker pain, discomfort or an uneasy feeling. It is used for physical difficulty (足が痛くて歩きづらい) and very often for psychological difficulty, such as feeling awkward or shy (先生に言いづらい, 友だちに頼みづらい). The point is the burden that the person doing the action feels.
leave ... as is / keep ...ing (negative nuance)
〜っぱなし has two main uses. First, something is left in a state that should normally be changed or finished: 電気をつけっぱなし (leaving the light on), 窓を開けっぱなし (leaving the window open). Second, the same action or state continues for a long time: 立ちっぱなし (standing the whole time), 負けっぱなし (losing again and again). In both uses it often shows that the speaker thinks it is careless, tiring or not good.
-ness (nominalizing suffix)
〜み turns an adjective into a noun that names a quality you feel with your body or heart, such as a taste, a pain or an emotion: 甘み (sweet taste), 痛み (pain), 悲しみ (sadness), 温かみ (warmth of feeling). Some words have a special meaning: 楽しみ (something you look forward to), 強み (a strong point), 重み (importance, weight of meaning). Compared with 〜さ, which often shows a degree or an amount, 〜み feels more concrete and personal.
Made for / intended for
〜向け shows who a product, service or piece of information was made for. The maker had that target in mind from the start. It is very common in shops, advertisements and news: 子ども向けの本 is a book that was written for children.
Suitable for / facing (a direction)
〜向き has two uses. With a person or a purpose, it means that something is suitable for them: 初心者向きの山 is a mountain that is good for beginners. With a direction word (東・西・南・北), it shows which way something faces: 南向きの部屋 is a room that faces south.
Keep -ing more and more (a change that goes in only one direction)
〜一方だ says that a change keeps going in one direction and shows no sign of stopping. It is used mostly for changes the speaker is not happy about, such as prices going up or health getting worse. It is a little formal and is common in news and written Japanese.
So ... that / to the extent that
This pattern shows how strong a state or feeling is by giving an example or a comparison: 死ぬほど疲れた means 'I am so tired I could die'. The part before ほど / くらい is often not something that really happens; it is a picture of the degree. ほど and くらい mean almost the same here, but くらい is a little more casual.
Nothing is as ... as / there is no ... like
This pattern says that A is number one: 'there is nothing as ... as A'. The sentence ends in a negative, but the meaning about A is strongly positive (or strongly negative, with a word like つらい). It shows the speaker's own feeling or opinion, so it is common when you praise or complain. くらい is a little more casual than ほど.
The more ..., the more ...
This pattern says that when one thing increases in degree, another thing changes together with it: 'the more you do A, the more B'. The same word is said twice, first in the ば-form and then before ほど. The second half of the sentence usually shows a change or a degree, such as 上手になる, 難しい or いい.
As much as (possible / you want)
This だけ does not mean 'only'. It means 'up to the limit': as much as you can, as much as you want, or as much as you need. The word before だけ sets that limit, and the verb after it says what you do up to that limit: 食べられるだけ食べる means 'eat as much as you can eat'.
Compared with / compared to
〜に比べて names the thing you use as a standard, and the sentence then says how something else is different from it. It is often used for changes over time (去年に比べて, 先月に比べて) and for differences between places or people. に比べて and と比べて have almost the same meaning. It sounds a little more formal than より.
Unlike / different from
〜と違って means 'unlike A': it takes A as a point of comparison and says that B is not like A. It is used for differences between people, places and times, and also for 'different from what I expected or heard' (思っていたのと違って, 天気予報と違って). The main sentence talks about B, not A.
Rather than (saying) A, B
〜というより is used when you first think of one word for something, and then choose a better one: 'it is not really A; B is a better way to say it'. It does not compare two different things; it compares two ways of describing the same thing. The more accurate word always comes after というより.
Considering / for (more or less than expected)
〜わりに says that, considering A, the result B is more or less than you would expect. A is often a degree or amount (price, age, how much you studied), and B is the speaker's evaluation. It can be positive (値段のわりにおいしい: tasty for the price) or negative (たくさん勉強したわりに点が悪い).
For a ... / considering that ... (unexpectedly)
〜にしては takes a fact (A) and says that the result (B) is different from what is normal for A: 'for a child', 'for September', 'for a first try'. It shows the speaker's surprise, and B can be praise or criticism. B is something that goes against the normal image of A, not something you would expect from it.
Even though (with criticism)
'A くせに B' means 'even though A, the person does B', and the speaker is angry, annoyed, or looks down on that person. It is like のに, but the feeling of blame is much stronger. Usually both parts are about the same person, and that person is not the speaker. It is used in conversation and can sound rude, so do not use it about your teacher or boss to their face.
Thanks to
'A おかげで B' means 'thanks to A, B': A is the cause of a good result B, and the speaker feels thankful for it. B is usually something that has already happened or a state that is true now. Sometimes people use おかげで with a bad result as sarcasm: 君が寝坊したおかげで… ('thanks a lot to you...'). For a bad result said plainly, use せいで.
Because of (blame) / maybe because of
'A せいで B' means 'because of A, the bad result B happened', and the speaker blames A for it. 'A せいか B' means 'maybe because of A, B': the speaker thinks A is probably the cause but is not sure. The result after せいで is bad; the result after せいか is often bad too, but it can also be neutral. B is a result, not a request or an invitation.
Due to / caused by
'A によって B' means 'B happened because of A'. It shows the cause in a formal, objective way, so it is common in news, reports and written explanations. B is usually a fact, often damage or a change, and not the speaker's wish or a request. This によって is different from によって for a means (by), for differences (depending on), and for the doer in a passive sentence (written by).
Since (as we both know)
'A のだから B' presents A as a fact that both the speaker and the listener know or must accept, and from that fact the speaker gives a strong judgment, advice, request or criticism B. It feels like 'since A is true (you know that), of course B'. It is stronger than から and can sound pushy. At the end of a sentence, 〜んだから shows that the speaker is annoyed.
Because (giving an excuse)
'A ものだから B' gives a personal reason A for B, often to explain or excuse something bad such as being late or making a mistake. It has the feeling 'it couldn't be helped, because A'. もので is a little softer and is common in polite apologies. The second part is usually a fact or a result, and it is not usually an order or an invitation (〜なさい, 〜ましょう).
Precisely because
'A からこそ B' stresses that A is the real and important reason for B: 'it is precisely because of A that B'. Sometimes A looks like a reason for the opposite (忙しいからこそ、休みが大切だ), and からこそ shows the speaker's strong opinion. It is usually used for positive or meaningful reasons, and not for simple bad reasons like oversleeping.
The reason ... is that ...
This pattern first states a fact or result, and then gives its reason at the end: 'the reason (that) A is (that) B'. Putting the reason last makes it the important, new information. It is used in speech and writing when you explain a reason clearly, answer 'why?', or correct a wrong idea.
The reason is that / because
First you say your conclusion or opinion, and then なぜなら introduces the reason, which ends with からだ / からです. It works like 'This is so. The reason is that ...'. It is used mainly in writing, speeches and presentations; in everyday conversation it sounds stiff, and people often say どうしてかというと or just use から instead.
Supposing that / if it is true that
'A としたら B' means 'if we suppose that A is true (or will happen), then B'. A is something imagined, or information you have heard but are not sure about, and B is often a guess, judgment, question or wish. The three forms mean almost the same thing; としたら is the most common in conversation, and とすれば / とすると sound a little more logical. They are usually not used for things that will surely happen.
Even supposing that / even if
'A としても B' means 'even if we suppose A, B (still)'. The speaker imagines A, or accepts A for the moment, and says that B does not change because of it. B is often the speaker's decision, opinion or guess. This としても is different from 〜として ('as', a role), even though it looks similar.
Even if / even for
'A にしても B' means 'even if A (is so), B': the speaker accepts A, or supposes it, but says B is still true. B is often the speaker's opinion, criticism or advice, for example 'that is too much' or 'you should still do this'. A is often something that is probably true, not only an imagined case. Some textbooks also teach にしても at N2.
Even if (strong supposition)
たとえ is an adverb that makes 〜ても stronger. 'たとえ A ても、B' means 'even if A were true, B would not change'. A is usually a supposed situation, often an extreme or unwelcome one, and B is often a strong decision or something that stays the same. It is usually not used for something that has actually happened.
If only / as long as
'A さえ B ば、C' means that if this one condition is met, C will happen, and nothing else is needed. It shows the minimum condition: 'as long as', 'all you need is'. With a past or のに ending, it shows regret that this one small thing was missing (地図さえあれば、道に迷わなかったのに). This さえ is different from the さえ that means 'even' (子どもでさえ知っている).
If only ... (then ... would have happened)
This pattern imagines a situation that is different from reality and says what would happen (or would have happened) in it. のに at the end adds regret, disappointment or a light complaint. The listener understands that the reality is the opposite: 早く出れば、間に合ったのに means 'I didn't leave early, so I didn't make it'. It is used for your own regrets and also for complaints about other people (言ってくれれば手伝ったのに).
I should have / I wish I had
〜ばよかった expresses regret about the past: 'I should have done it (but I didn't)'. The negative 〜なければよかった means 'I shouldn't have done it (but I did)'. When you say 〜ばよかったのに about someone else, it sounds like 'You should have...', with sympathy or a light complaint. It is about something that is already over, so it is not used to give advice about the future.
Why don't you ... / How about ...
〜たらどうか suggests an action to someone: 'How about doing ...?'. The person who does the action is the listener or another person, not the speaker. At N3 you meet the plain どうか in writing and in reported suggestions (〜たらどうかと言われた), and the short casual forms 〜たらどう？ and 〜たら？ in conversation. Said in a sharp tone, 〜たらどう？ / 〜たらどうなの can sound like criticism: 'Why don't you just ...!'.
When I did ..., I found / it happened
'A たら／と、B（past）' says that when someone did A, they found B, or B happened right after A. A has really happened, so this is not 'if'. B is something outside the speaker's control: a state they noticed, a surprise, or a change that A led to. たら is common in conversation; と is common in stories and writing.
When I did ..., it turned out that
'A たところ、B' means 'when I did A, the result was B / I found out B'. A is usually something done on purpose to find out or to try (asking, checking, trying), and B is the result or the new information. It is more formal than the discovery 〜たら, so it is common in reports, emails and news. It is different from 〜たところだ at the end of a sentence, which means 'have just done'.
It's no use -ing / It can't be helped if
This pattern has two uses. (1) After an action: doing it is useless because it will not change anything (今さら後悔してもしかたがない: there's no point regretting it now). (2) After a bad result: given the situation, it is natural or understandable, so you have to accept it (三回も遅れたのだから、怒られてもしかたがない: it's only natural to be scolded). Both uses carry a feeling of giving up or accepting something you don't like.
Although I say ... / It's ..., but only
'A といっても、B' means 'It is true that A, but B': the speaker admits A, then corrects what the listener might imagine from it. B usually shows that the real degree is smaller or different from what A suggests (料理ができるといっても、簡単なものだけです). It is often used to be modest or to give a more exact picture.
On the other hand / While
'A 一方（で）、B' puts two things side by side. It can show two different sides of one thing (便利な一方で、家賃が高い), a contrast between two people or things (兄は〜一方、弟は〜), or two activities that someone does in the same period (働く一方で、大学で勉強している). It sounds a little formal and is common in writing and the news.
On the flip side / But at the same time
'A 反面、B' shows two opposite sides of one person or thing: A is often a good point and B a bad point, or the other way round. The two sides should really be opposite, so two good points (or two bad points) do not fit. It sounds a little formal and is common in writing, but it is also used in speech.
In contrast to / Whereas
'A のに対して、B' puts two different people or things side by side and shows that they are opposite or clearly different: 'A is X, whereas B is Y'. It states the difference as a fact, without surprise or complaint, so it is common in explanations, reports and comparisons with numbers. This is different from 〜に対して meaning 'toward / against' (先生に対して).
Contrary to (expectations, hopes)
〜に反して says that what actually happened is the opposite of what people expected, forecast or hoped. The part before に反して names the expectation, and the part after it tells the real result. It sounds a little formal and is common in news and writing. In casual talk, people often use 〜と違って instead.
Even (an extreme example)
〜さえ picks out an extreme example: something very easy, basic or unexpected. The message is 'even X, so of course the others too'. For example, ひらがなさえ書けない means the person can't write even hiragana, so kanji is out of the question. It is often used with negative or 'can / can't' sentences, and it can also show surprise in positive sentences.
It is precisely ... that / this time for sure
〜こそ strongly points to one thing and says 'this one, and not any other'. It is used to say that something is the most important or the true one (これこそ本物だ), to show strong determination after a failure (今度こそ合格したい), and in the polite reply こちらこそ ('it is I who should say that'). It usually stresses something the speaker sees as important or right.
Things like / the likes of (example, modesty, making light)
At N5 you learned など for listing examples (AやBなど). At N3, noun + など / なんか is also used with just one noun, in three ways. (1) To offer one example softly: このシャツなんかどう？ (2) To be modest about yourself: 私なんか、まだまだです. (3) To make something sound unimportant or to show dislike: 宿題なんか簡単だ, 虫なんか大きらい. The meaning comes from the context, and なんか is the more casual and emotional of the two.
Such a thing as / to think that (surprise, scorn)
〜なんて takes up a thing or a fact and shows the speaker's strong feeling about it. After a whole sentence, it usually shows surprise or disbelief: 'to think that ...!'. After a noun, it often makes the thing sound unimportant or shows dislike, like なんか. It is casual and emotional, so it is common in conversation.
Do nothing but / always be doing
〜てばかりいる says that someone does the same action again and again, or all the time, and does not do other things they should do. It usually carries the speaker's criticism, worry or complaint. It does not have to be 100% true; it means 'so often that it feels like nothing else'. 〜てばかりいないで is a common way to tell someone to stop doing only one thing.
Not only ... but also
〜ばかりでなく means 'not only A, but also B'. It gives one fact and then adds another fact of the same kind. It means almost the same as だけでなく but sounds a little more formal, so it is common in writing and news. 〜ばかりか is stronger: the added part is often more surprising or more extreme, as in 'not only A, but even B'. ばかりか is often studied at N2.
Not only ... but also
〜だけでなく means 'not only A, but also B'. だけ ('only') + でなく ('is not') says that A is not the only one, and the second part adds B, usually with も. It is the most common way to say 'not only ... but also' and works in conversation, writing, requests and advice.
Not to mention / A, of course, and also B
〜はもちろん means 'A, of course, and B too'. A is the obvious case that everyone would expect, and the second part adds B, which is less obvious. In negative sentences, A is the bigger thing that is clearly impossible, and B is a smaller thing that is also impossible: 旅行はもちろん、散歩にも行けない. It is used in both conversation and writing.
Regarding / about (formal)
〜に関して shows the topic of talking, writing, asking or research: 'regarding X' or 'about X'. The meaning is almost the same as について, but に関して is more formal. It is common in news, business, school notices and official writing. In everyday conversation with friends, について is more natural.
Toward / to (the target of an action or feeling)
〜に対して shows the person or thing that an action, an attitude or a feeling is aimed at: 'toward', 'to' or 'against'. It is used for how you treat people (kind, polite, strict), how you respond (answer, protest), and what you feel (angry, grateful). It is a little more formal than the simple particle に. (に対して for contrast, 'whereas', is a separate pattern.)
For / from the standpoint of
〜にとって means 'for X' in the sense of 'from X's point of view'. It shows whose standpoint is used to judge something as important, difficult, useful, and so on. The part after it gives that judgment, usually with an adjective, a noun + だ, or an evaluating verb such as 役に立つ or 〜になる. It is not followed by a simple action or a wish.
As (in the role of)
〜として shows the role, position, or kind of thing in which someone or something acts or is seen: 'as a student', 'as a meeting room'. The noun before it tells you in what capacity the action happens. 〜としては often introduces an opinion from someone's position, and 〜としての connects to a following noun.
By means of / through
〜によって shows the method or means used to do something: 'by discussion', 'through a survey'. It sounds more formal than で and is common in news, reports, and official notices. It is often used with verbs like 決める, 解決する, 集める and 連絡する, where a method leads to a result.
Depending on / in some cases
〜によって says that something is different for each N: 'it differs from country to country', 'it depends on the day'. The rest of the sentence usually has a word like 違う or 変わる. 〜によっては picks out some of those N and says what can happen in their case: 'in some cases', 'for some people'.
In / at (formal)
〜において means the same as で (place or situation) but is formal. It is used in writing, news, speeches, and official notices, for example when saying where an event is held or in what field something is true. In everyday conversation, で is normally used instead.
In place of (a person / thing)
〜にかわって means that someone or something takes the place of the noun before it. It is used when one person does another person's job for a time (the manager is away, so I speak instead), and when something new replaces something old (email in place of letters). It sounds a little formal and is common in speeches, announcements and news.
Instead of / in exchange for
〜かわりに has two main uses. First, 'instead of': you do or use B, not A (coffee → tea, going out → reading at home). Second, 'in exchange for / to make up for': one thing is balanced by another, as in 'I teach you English, and in return you teach me Japanese'. With adjectives, it often means a thing has one good point and one bad point: 'far from the station, but cheap'.
Starting with / including
〜をはじめ gives one main or typical example first, and then talks about the whole group that includes it: 'the president and all the other staff', 'temples and many other old buildings'. The noun before it is usually the most important or best-known member of the group. It sounds a little formal and is common in speeches, news and writing.
Centering on / mainly
〜を中心に says that the noun is the center or the main part of something. It is used for places (shops are gathered around the station), for people (a group led by Linh), and for 'mainly' (popular mainly with young people; rain mainly in the Kanto area). Other things are also included, but the noun is the core.
Through / via / throughout
〜を通して has two uses. First, 'through / via': something reaches you by way of a person, a medium, or an experience (I met my wife through a friend; I learned through my part-time job). Second, 'throughout': the same state continues for a whole period (warm all year round). を通じて has the same meaning and sounds a little more formal.
Taking ... as an opportunity / triggered by
〜をきっかけに names an event that gave someone the chance or the push to start something new or to change. The second half usually says what began or changed: started studying, quit smoking, came to like something. The event before it is often one moment (an illness, a move, a meeting), and what follows is a new development.
Filled with (feeling) / with all one's heart
〜をこめて means that you put a feeling or a wish into something you make or do: cooking with love, writing a letter full of thanks, singing with a wish for peace. The noun before it is almost always a feeling word. 心をこめて is a very common set phrase meaning 'with all one's heart / carefully and sincerely'.
As ... (changes), ...
〜につれて shows that when one thing changes little by little, another thing also changes little by little: 'as time passes, the town changes'. Both halves are gradual changes, so the second half often ends with 〜なる, 〜てくる, 〜ていく or 〜ようになる. It describes a change that happens naturally, so it usually does not end with a request or the speaker's plan.
As ... (changes) / in accordance with, following
にしたがって has two uses. First, A にしたがって B means 'as A changes, B also changes little by little'; both A and B are gradual changes. Second, noun + にしたがって means 'following' a rule, an instruction or a guide, and doing what it says. The tone is a little formal, so it is common in explanations, news and written Japanese.
Together with / at the same time as / as ... changes
とともに has three main uses. With a person, it means 'together with' and is a more formal way to say と一緒に. With an event, it means 'at the same time as' (卒業とともに = right when I graduate). With a change, it means 'as A changes, B changes too', like につれて. It sounds formal, so it is common in speeches, news and writing.
In order to / to do ... (you need, it takes)
A には B means 'to do A, B is needed / B is best / it takes B'. A is a goal, and B tells you what is necessary for it, how to reach it, or how hard or easy it is. B is usually a judgment or a question, not a report of one action someone actually did. It is common when asking for or giving advice and directions.
Particle + の to describe a noun (への, での, からの, との)
A particle like へ, で or から normally connects a noun to a verb (友だちへ送る, 日本で生活する). To connect it to another noun instead, you add の after the particle: 友だちへの手紙 = a letter to a friend. The particle keeps its meaning (direction, place, starting point, partner, end point), so the phrase is clearer than noun + の + noun alone.
No wonder / that means / so that's why
わけだ shows a conclusion that follows naturally from a fact. In one use, the speaker learns a reason and now understands a situation they already knew about: 'no wonder'. In another, the speaker works out what a fact means: 'so that means ...'. In both cases, there is a clear reason or fact behind the statement.
It doesn't mean that / it's not that / not necessarily
わけではない denies a conclusion that the listener might draw from a situation. It does not deny everything; it says 'that is not the whole story' or 'not always'. It often goes with words like いつも, みんな, 全部 and 別に, and it is common when explaining your feelings or reasons: 嫌いなわけではない = it's not that I dislike it.
There is no way that / it is impossible that
わけがない strongly denies a possibility: from what the speaker knows, something is impossible or cannot be true. It is the speaker's own firm judgment, often with a reason given before it. It is common in conversation, and そんなわけない is a set phrase meaning 'No way!'.
Cannot (because of duty, manners or the situation)
わけにはいかない means that you are able to do something, but you cannot do it because of your duty, good manners, other people's feelings or the situation. It is not about ability: the speaker judges that doing it would be wrong or inappropriate. It often comes after a reason with から or ので.
Have to / cannot not do (because of duty or the situation)
〜ないわけにはいかない means 'I cannot not do it', so 'I have to do it'. The reason is usually a duty, a relationship or the situation, not the speaker's wish. It often suggests that the speaker would rather not do it, but feels it would be wrong or rude to avoid it.
Should / should not (what is right to do)
べきだ gives the speaker's strong opinion about what is right or proper to do, based on common sense, morals or the role of a person. It is stronger than 〜たほうがいい and can sound like a lecture when used directly to someone. べきだった looks back with regret: 'I should have done it (but I didn't)'.
Must be / there is no doubt that
に違いない shows that the speaker is almost completely sure about something, often because of something they see or know. It is a judgment or conclusion about a fact, not a plan. It is a little formal and is common in writing and stories; in everyday conversation, people often use きっと〜と思う or 〜はずだ instead.
Surely / of course / it's bound to be
に決まっている shows that the speaker is completely sure, as if there could be no other answer. It is the speaker's own strong, sometimes one-sided belief, and it is mainly used in conversation. It is often used to say 'of course' in reply to a question, or to warn someone about an obvious result.
There is a risk that / might (something bad)
〜おそれがある says that something bad or unwanted may happen. It is a formal expression, so you often hear it in weather reports, news and official notices. It is used for bad results such as storms, damage, illness or delays, not for good news.
Not necessarily / not always
〜とは限らない means 'not necessarily'. It says that something people usually believe is not true in every case, and that there are exceptions. It is a partial negation: 高い物がいい物だとは限らない does not mean expensive things are bad, only that they are not always good. The adverb 必ずしも (not always) is often put in front to make this meaning clear.
I suspect that / isn't it that ...?
〜のではないか shows the speaker's guess: 'I think that it may be so'. Although it has ない, it is not a negative sentence. 難しいのではないか means 'I think it is difficult'. It is also a soft way to give an opinion, because the speaker does not say it too strongly. In conversation it becomes 〜んじゃないか or 〜んじゃない？.
It's not that ... can't / not impossible
This pattern uses two negatives to make a weak 'yes'. 行けないことはない means 'it's not that I can't go', so 'I can go, but...'. The speaker admits that something is possible or true, but is not very positive about it, and often adds a reason or a condition after が or けど. こともない sounds a little softer than ことはない.
It's true that ..., but / I did ..., but
〜ことは〜が admits that something is true, but says it is not enough or not the whole story. 読むことは読んだが means 'I did read it, but (I didn't understand it well)'. The part after が or けど gives the problem or the limit. It is useful when you agree only partly, or when the result was not as good as hoped.
You should / the best thing is to (advice)
〜ことだ gives strong advice: 'the most important thing is to do ...'. The speaker says what the listener should (or should not) do to get a good result. Because it sounds like advice from someone with more experience, it is usually used by teachers, parents, seniors or experts, and not toward someone in a higher position.
There's no need to / you don't have to
〜ことはない tells someone that an action is not necessary. It is often used to comfort or calm the listener: 心配することはない means 'there's no need to worry'. The past form 〜ことはなかった looks back and says 'there was no need to do that'. After the dictionary form, ことはない can also mean 'it never happens' (この店が休むことはない), so read the context.
How ...! / So very ...! (strong feeling)
〜ことか expresses a very strong feeling: 'how (much) ...!' or 'so many times!'. It looks like a question, but it is not one, and no answer is expected. The speaker is saying that the degree is very high, as in どんなに心配したことか (How worried I was!). It is a little literary and is common in writing and emotional speech.
Must / do ... (written instruction or rule)
Ending a sentence with 〜こと gives an instruction or a rule: 'you must do ...' or 'do not ...'. It is used in written rules, notices, exam instructions and school handouts. Teachers and parents also use it when they state rules to students or children. Because it is a short, direct order, it is usually not used when you speak politely to customers or superiors.
I hear that / they say (reporting information)
〜ということだ and 〜とのことだ report information that the speaker heard or read: 'I hear that ...' or 'I'm told that ...'. They sound more formal than 〜そうだ and are common in news and business. とのことだ is often used to pass on a message from someone else, for example on the phone at work: 田中さんから、少し遅れるとのことです.
It means that / in other words (conclusion)
〜ということだ here explains what something means or states a conclusion drawn from a fact: 'that means ...' or 'in other words ...'. The speaker looks at a situation or at what someone said and puts its meaning into other words. In the question form 〜ということですか, you check whether you have understood correctly. This is different from the hearsay 〜ということだ, which reports information from someone else.
What ... means is / the thing called ... is
〜というのは picks up a word, name or idea as the topic in order to explain or define it: 'what X means is ...'. The sentence usually ends with 〜のことだ, 〜という意味だ or an opinion about it. You also use it to ask about a word you don't know: 〜というのは何ですか. At the start of a sentence, というのは introduces the reason for what you have just said, and the sentence usually ends with 〜からだ.
the (news / idea / fact) that ...
In 'A という B', A is a whole sentence that tells the content of B: 合格したという知らせ is 'the news that (someone) passed'. B is a noun that carries information, such as news, a story, a rumor, an opinion, an idea or a message. ということ works in the same way and turns a sentence into a noun, so you can put が, を or は after it: 'the fact that ...'. This is a step up from the N4 use, where the part before という is only a name (さくらというレストラン).
speaking of ... / when you say ...
'X といえば Y' takes up a topic X and says the first thing that comes to mind about it, usually something typical or famous: 夏といえば花火 (speaking of summer, fireworks). It is also used when a word someone just said reminds you of something to talk about next. というと is often used to check what the other person means (A: 田中さんが… B: 田中さんというと、背の高い田中さんですか). といったら is a little more casual and emotional in conversation.
that's how things are / one should
〜ものだ says that something is true by nature or in general, not just this one time: 人は間違えるものだ (people make mistakes; that's how people are). It is also used for common sense about how people should act: 約束は守るものだ (you should keep your promises). It often adds a feeling that the speaker has noticed or accepted this truth, as in 楽しい時間は早く過ぎるものですね.
used to ... (looking back fondly)
〜たものだ looks back on something the speaker often did or that often happened in the past, with a feeling of missing those days: 子どものころは、よくこの川で泳いだものだ (when I was a child, I often used to swim in this river). In this nostalgic meaning, it is used for habits that went on for some time, not for something that happened only once. It often suggests that things are different now.
one shouldn't ...
〜ものではない gives general advice based on common sense or good manners: 'one shouldn't do that'. It is often used by parents, teachers or older people when they warn or scold someone: 人の悪口を言うものではない (you shouldn't speak ill of others). It is not about a written rule or one person's plan; it is about what people in general should not do. With a potential verb (なれる, できる), it says something is not easy to do.
no way ...! / as if I would!
〜ものか is a strong, emotional 'no'. It has two main uses. (1) A firm decision not to do something: あんな店、二度と行くものか (I'll never go to that shop again!). (2) Strongly rejecting what someone else said or thinks: 「簡単でしょう？」「簡単なものか」 (Easy? It's not easy at all!). It is spoken language, said with a falling tone, and it can sound rough, so it is not used in formal situations.
believe that one has done / as if, with the feeling that
Here つもり is not a plan. 〜たつもりだ says what the speaker believes they did, often when the facts or other people's views are different: 鍵をかけたつもりだった (I thought I had locked it, but ...). With adjectives and nouns it shows how someone sees themselves, which may not match reality: 父はまだ若いつもりだ. 〜つもりで + action means doing something while imagining that something is true: 旅行に行ったつもりで、そのお金を貯金した (I saved the money, telling myself I'd already been on the trip).
unbearably ... / dying to ...
〜てたまらない says that a feeling or a body sensation is so strong that the speaker can hardly stand it: 暑くてたまらない (it's unbearably hot), 会いたくてたまらない (I'm dying to see them). It is used with words for feelings and sensations, such as うれしい, 心配, 寂しい, 痛い, 眠い, 〜たい and 気になる. It usually describes the speaker's own feelings; for other people, ようだ, らしい or そうだ is usually added.
can't help feeling ... / extremely ...
〜てしかたがない says that a feeling or a body sensation is so strong that the speaker can't control it: 心配でしかたがない (I can't stop worrying). It is also common with things that happen by themselves, like 気になる or 涙が出る. しょうがない is the more casual, spoken form. Do not confuse it with 〜てもしかたがない, which has も and means 'there's no point in ...'.
after all the trouble / since (this rare chance) ...
せっかく shows that something is valuable: an effort someone made or a rare, good chance. With のに, the value was wasted, so the speaker feels sorry or disappointed: せっかく作ったのに、誰も食べなかった (I went to the trouble of cooking, but nobody ate). With のだから / から, the speaker wants to make good use of the chance, so a wish, suggestion or decision follows: せっかく来たんだから、写真をとろう (since we came all this way, let's take photos). せっかくですが is a polite way to turn down an offer while showing thanks.
go out of one's way to / take the trouble to
わざわざ says that someone did something that took extra time or effort and was not really necessary, instead of doing it the easy way or on the way to somewhere else. When the action is for you, it shows thanks: わざわざ来てくれてありがとう (thank you for taking the trouble to come). It is also used to say an effort is not needed, or to wonder why someone chose the harder way: わざわざ遠くの店まで行ったの？
(do) without meaning to / can't help (doing)
つい〜てしまう says that someone did something they didn't mean to do, because of habit, temptation or a moment of carelessness, and often feels bad about it: ダイエット中なのに、つい甘い物を食べてしまう (I'm on a diet, but I end up eating sweets). The present form (〜てしまう) is used for things that happen again and again; the past (〜てしまった) for one time. つい is used for actions a person does, not for things that happen by luck. (With time words, つい has another meaning, 'just': ついさっき = just a moment ago.)
no matter what / by all means
With a negative, どうしても says that something does not work or cannot be done, even though the speaker has tried many ways. With a wish or a need, it says that the speaker wants or needs something very strongly and will not give up. With 〜てしまう, it means the speaker cannot stop themselves from doing something. It shows strong feeling, so it is common when you explain a difficulty or make a serious request.
rarely / hardly ever
めったに〜ない says that something happens very rarely: not zero times, but almost never. It is about frequency (how often), so it is used with verbs, not to show the degree of an adjective. It is stronger than あまり〜ない and weaker than ぜんぜん〜ない. The set phrase めったにない means 'rare, hard to find'.
never / by no means
決して〜ない is a strong negative. With a verb, it often shows the speaker's firm decision ('I will never ...') or a strong warning ('Never do ...'). With an adjective or noun, it strongly denies an idea: 'it is by no means ...'. It sounds serious and a little formal, so it is common in writing, speeches and warnings.
not at all / not even a little
少しも〜ない and ちっとも〜ない mean 'not at all, not even a little'. They make the negative complete. ちっとも is casual and is used in conversation, often with a feeling of complaint or surprise. 少しも can be used in both speech and writing, and 全く〜ない sounds the most formal. Note that 全く can also be used in affirmative sentences (全く同じだ, 'exactly the same'), but 少しも and ちっとも are used with a negative.
surely not / I never thought that ...
まさか shows that the speaker thinks something is almost impossible. With 〜ないだろう or 〜はずがない, it means 'surely it won't happen': the speaker strongly believes it is not true. With 〜とは思わなかった, something that the speaker never expected has really happened, and the speaker is surprised. In a question like まさか〜の？, it means 'Don't tell me ...!'
however (contrary to expectation)
ところが introduces a result that goes against what sentence A made you expect. It often carries surprise, and the result can be bad or good. It is common when telling a story or explaining what happened. Because B is a fact that the speaker did not expect, ところが is not used before your own opinion or request; use でも or しかし for those.
by the way
ところで is used to change the topic: 'by the way'. It shows that the speaker is finished with the last topic and now wants to talk about something else. It is often used after small talk to move to the real business, or to ask about something that has just come to mind. It does not show contrast or a result.
thereupon / then / in that case
In its first use, すると says that right after someone did A, B happened or was discovered. B is something the speaker does not control: a change, a reaction or a new fact. It is common in stories and written explanations. In its second use, すると takes what the other person just said and draws a conclusion from it, like 'then' or 'in that case'.
moreover / on top of that
そのうえ and しかも add one more point on top of what was just said. The two points go in the same direction: good + good, or bad + bad. そのうえ sounds a little formal and is common in writing. しかも puts more stress on the added point and is often used when that point is surprising or especially important.
in other words / in short
つまり is used to say something again in a different, clearer way, or to give the conclusion that follows from what was said. 要するに is used to sum up the main point, often after a long or complicated explanation. Both are common when you check what the other person means: つまり、〜ということですか. 要するに can sound a little impatient, as if the speaker wants to skip the details.
therefore / for that reason (formal)
したがって and そのため both mean 'therefore': B follows from A. そのため points back to A as the cause ('because of that'), so it is common for events such as delays, cancellations and changes. したがって sounds more logical and more formal, and it is often used when B is a conclusion you can reason out from A, as in rules, calculations and explanations. In everyday conversation, だから or それで is used instead.
written-style copula (である style)
である has the same meaning as だ and です, but it is used in formal writing: essays, reports, newspaper articles and textbooks. It sounds objective and serious. A text written in である style uses plain forms everywhere and does not mix in です / ます. In conversation it is rarely used, except in speeches.
stem form used to connect clauses (written style)
This is the written partner of the て-form. Instead of 〜て、 or 〜くて、, written Japanese often uses the ます-stem or 〜く to join two clauses. The meaning is the same as with the て-form: actions in order, two facts side by side, or sometimes a light cause. It is common in newspapers, reports, essays and formal speeches, and it often appears together with である style. The last predicate of the sentence shows the tense and the politeness.